Maybe I'm an idiot, but if someone has punched me in the face and is trying to knock me unconscious by slamming my head on the concrete, they're using deadly force on me. My common sense,especially during a beating while calling for help is use anything at my disposal to make the beating end, even if it involves deadly force.
Anyone who would disagree needs to have their nose broken and their head slammed against the concrete repeatedly until common sense allows them to think clearly.
fistfight deaths most by hitting head on concrete:
coma after shoved into wall
brain injury no external evidence